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1.
J Pharm Biomed Anal ; 248: 116299, 2024 Jun 08.
Article in English | MEDLINE | ID: mdl-38865928

ABSTRACT

Infections caused by microorganisms are a public health problem worldwide. New biodetection systems are essential to diagnose with accuracy resulting in more effective treatment. In this work, we propose a ConA-conjugated graphene quantum dots and polypyrrole film-based biosensor for label-free detection of Candida albicans, Candida glabrata, Candida tropicalis, E. coli, B. subitilis, and S. aureus. We modified polypyrrole and graphene quantum dots (PPY-QDGs) with Concanavalin A (Con A) lectin. ConA is a glucose/mannose-specific lectin. The results showed that ConA lectin has the highest binding affinity for C. tropicalis and S. subtilis. PPY-GQDs-ConA binding profile revealed differential response for Candida spp (C. tropicalis > C. albicans > C. glabrata) and bacterial (B. subtilis > S. aureus > E. coli). The limits of detection (LOD) obtained were 1.42 CFU/mL for C. albicans, and 3.72 CFU/mL for C. glabrata. C. tropicalis yielded a LOD of 0.18 CFU/mL. The respective LODs for the evaluated bacteria were 0.39 CFU/mL for S. aureus, 0.72 CFU/mL for S. subtilis, and 2.63 CFU/mL for E. coli. The differential response obtained for the sensor can be attributed to the heterogeneous distribution of carbohydrates on the microorganism's surfaces. The proposed system based on a flexible substrate is effective for microbiological diagnosis.

2.
Sci Rep ; 14(1): 956, 2024 01 10.
Article in English | MEDLINE | ID: mdl-38200060

ABSTRACT

The timely and accurate diagnosis of candidemia, a severe bloodstream infection caused by Candida spp., remains challenging in clinical practice. Blood culture, the current gold standard technique, suffers from lengthy turnaround times and limited sensitivity. To address these limitations, we propose a novel approach utilizing an Electronic Nose (E-nose) combined with Time Series-based classification techniques to analyze and identify Candida spp. rapidly, using culture species of C. albicans, C.kodamaea ohmeri, C. glabrara, C. haemulonii, C. parapsilosis and C. krusei as control samples. This innovative method not only enhances diagnostic accuracy and reduces decision time for healthcare professionals in selecting appropriate treatments but also offers the potential for expanded usage and cost reduction due to the E-nose's low production costs. Our proof-of-concept experimental results, carried out with culture samples, demonstrate promising outcomes, with the Inception Time classifier achieving an impressive average accuracy of 97.46% during the test phase. This paper presents a groundbreaking advancement in the field, empowering medical practitioners with an efficient and reliable tool for early and precise identification of candidemia, ultimately leading to improved patient outcomes.


Subject(s)
Candida , Candidemia , Pichia , Humans , Artificial Intelligence , Electronic Nose , Candida parapsilosis
3.
Future Microbiol ; 18: 1225-1233, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37882752

ABSTRACT

Aim: To evaluate antifungal potential of 5,6,7,8-tetrahydroimidazo[1,2-a]pyrazine hybrids based on thiosemicarbazones and thiazolidinediones against pathogenic Sporothrix species. Methods: Antifungal activity of nine compounds were assessed by broth microdilution. Interactions between active compounds and itraconazole were evaluated by the checkerboard assay using non-wild-type isolates. Cytotoxicity of the compounds was determined. Results: Four C-3 substituted analogs showed antifungal activity, unrelated to thiosemicarbazone or thiazolidinedione functions. Synergistic interactions between the four compounds and itraconazole, and low toxicity on mouse fibroblast cells were observed. Activity of 5,6,7,8-tetrahydroimidazo[1,2-a]pyrazine hybrids against Sporothrix depended on the substitution on the imidazopyrazine ring. Conclusion: Antifungal potential, overcoming itraconazole resistance and low toxicity indicate the possible use of that series of compounds in a therapeutic alternative for treatment of sporotrichosis.


Subject(s)
Sporothrix , Thiazolidinediones , Thiosemicarbazones , Animals , Mice , Antifungal Agents/pharmacology , Itraconazole/pharmacology , Thiosemicarbazones/pharmacology , Microbial Sensitivity Tests
4.
Biomedicines ; 11(9)2023 Aug 22.
Article in English | MEDLINE | ID: mdl-37760782

ABSTRACT

Schistosomiasis, a potentially fatal chronic disease whose etiological agents are blood trematode worms of the genus Schistosoma spp., is one of the most prevalent and debilitating neglected diseases. The treatment of schistosomiasis depends exclusively on praziquantel (PZQ), a drug that has been used since the 1970s and that already has reports of reduced therapeutic efficacy, related with the development of Schistosoma-resistant or -tolerant strains. Therefore, the search for new therapeutic alternatives is an urgent need. Plumbagin (PLUM), a naphthoquinone isolated from the roots of plants of the genus Plumbago, has aroused interest in research due to its antiparasitic properties against protozoa and helminths. Here, we evaluated the in vivo schistosomicidal potential of PLUM against Schistosoma mansoni and the in silico pharmacokinetic parameters. ADMET parameters and oral bioavailability were evaluated using the PkCSM and SwissADME platforms, respectively. The study was carried out with five groups of infected mice and divided as follows: an untreated control group, a control group treated with PZQ, and three groups treated orally with 8, 16, or 32 mg/kg of PLUM. After treatment, the Kato-Katz technique was performed to evaluate a quantity of eggs in the feces (EPG). The animals were euthanized for worm recovery, intestine samples were collected to evaluate the oviposition pattern, the load of eggs was determined on the hepatic and intestinal tissues and for the histopathological and histomorphometric evaluation of tissue and hepatic granulomas. PLUM reduced EPG by 65.27, 70.52, and 82.49%, reduced the total worm load by 46.7, 55.25, and 72.4%, and the female worm load by 44.01, 52.76, and 71.16%, for doses of 8, 16, and 32 mg/kg, respectively. PLUM also significantly reduced the number of immature eggs and increased the number of dead eggs in the oogram. A reduction of 36.11, 46.46, and 64.14% in eggs in the hepatic tissue, and 57.22, 65.18, and 80.5% in the intestinal tissue were also observed at doses of 8, 16, and 32 mg/kg, respectively. At all doses, PLUM demonstrated an effect on the histopathological and histomorphometric parameters of the hepatic granuloma, with a reduction of 41.11, 48.47, and 70.55% in the numerical density of the granulomas and 49.56, 57.63, and 71.21% in the volume, respectively. PLUM presented itself as a promising in vivo antiparasitic candidate against S. mansoni, acting not only on parasitological parameters but also on hepatic granuloma. Furthermore, in silico, PLUM showed good predictive pharmacokinetic profiles by ADMET.

5.
Future Microbiol ; 17: 1437-1443, 2022 12.
Article in English | MEDLINE | ID: mdl-36382573

ABSTRACT

Two cases of otomycosis have been reported in patients undergoing tympanomastoidectomy. The first one had chronic otitis media, hypertrophic concha and nasal septum deviation, tympanic perforation and otorrhea. The second had otalgia, pruritus, chronic otitis media and cholesteatoma. Direct examination showed mycelial septate filaments with a branch at an angle close to 45°, later identified as Aspergillus sydowii by sequencing the BenA and CaM genes. Susceptibility testing showed low MIC of amphotericin B, itraconazole, ketoconazole and ciclopirox olamine. In both cases, ketoconazole was instituted for 10 days. Otomycosis is a challenge as it is primarily recurrent in patients undergoing surgery. The clinical implication, the identification of the emerging pathogen and the determination of MIC were necessary for the knowledge of the epidemiological profile and establishment of the treatment.


Aspergillus are fungi that can cause ear disease. In severe infections, these fungi can be present for long periods inside the ear, and commonly belong to the species Aspergillus section Nigri and Aspergillus flavus. In this work, we present two cases of ear infections by a different species, Aspergillus sydowii. Patients had obstructed nasal cavities, crooked internal separation of the nose and complaints of secretion in the ear. The efficient diagnosis allowed a treatment that resulted in the death of the fungus and the cure of the patient.


Subject(s)
Otomycosis , Humans , Otomycosis/diagnosis , Otomycosis/drug therapy , Ketoconazole/therapeutic use , Aspergillus/genetics , Itraconazole/therapeutic use , Antifungal Agents/pharmacology , Antifungal Agents/therapeutic use
6.
Enzyme Microb Technol ; 160: 110088, 2022 Oct.
Article in English | MEDLINE | ID: mdl-35777193

ABSTRACT

The increasing number of multidrug resistance microorganisms is an alarming threat, and their rapid detection is essential to prevent nosocomial, foodborne, or waterborne infections. Many peptides derived from the venom of wasp Synoeca surinama have antimicrobial activity against Gram-positive and Gram-negative bacteria. Synoeca-MP, an antimicrobial peptide (AMP) from mastoparan family, seems to increase bacterial membrane permeability, promoting cytotoxicity and membrane disruption. Here Synoeca-MP was evaluated as biorecognition element tethered over chitosan-coated magnetic nanoparticles (Fe3O4-Chit). The transducing layer of the biosensor was developed from the self-assembling of 4-mercaptobenzoic acid (4-MBA) monolayer onto gold substrate. Atomic force microscopy (AFM) analyses confirmed the biointeraction between AMP and different pathogens membranes. The fabrication and performance of the biosensing assembly were characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Detection of Enterococcus faecalis (G+), Klebsiella pneumoniae (G-), Pseudomonas aeruginosa (G-), and Candida tropicalis was assessed in a recognition range from 101 to 105 CFU.mL-1. An instrumental limit of detection of 10 CFU.mL-1 was obtained for each specimen. However, the device presented a preferential selectivity towards Gram-negative bacteria. The proposed biosensor is a sensitive, fast, and straightforward platform for microbial detection in aqueous samples, envisaged for environmental monitoring applications.


Subject(s)
Biosensing Techniques , Magnetite Nanoparticles , Anti-Bacterial Agents/pharmacology , Biosensing Techniques/methods , Electrochemical Techniques/methods , Gold/chemistry , Gram-Negative Bacteria , Gram-Positive Bacteria , Intercellular Signaling Peptides and Proteins , Magnetite Nanoparticles/chemistry , Wasp Venoms
7.
Reprod Domest Anim ; 57(9): 1063-1073, 2022 Sep.
Article in English | MEDLINE | ID: mdl-35696284

ABSTRACT

Pyometra is one of the most common diseases in adult female dogs, characterized by a suppurative bacterial infection of the uterus with accumulation of inflammatory exudate and a variety of local and systemic clinical manifestations. This study aimed to identify the bacteria within the uterine content and vaginal canal of bitches with pyometra and evaluate their antimicrobial susceptibility and production of virulence factors. Uterine and vaginal content were collected with sterile swabs from 30 bitches diagnosed with pyometra. Bacteria were identified and assessed for their antimicrobial susceptibility and production of virulence factors, including biofilms, siderophores, proteases and hemolysins, both in planktonic and biofilm forms. A total of 82 bacterial isolates (35 uterus, 47 vagina), belonging to 21 species, were identified, with Escherichia coli as the most prevalent species (32/82, 39%). As for susceptibility, 39/79 (49.4%) isolates were resistant to one or more drugs, with resistance proportion among Gram-positive bacteria (87.5%) higher (p < .05) than that observed for Gram-negative bacteria (32.7%). Four coagulase-negative Staphylococcus species were resistant to methicillin. Regarding virulence, the isolates had low production of biofilms, siderophores, proteases and hemolysins, suggesting that the occurrence of pyometra might be more associated with host-related factors than bacterial virulence.


Subject(s)
Anti-Infective Agents , Dog Diseases , Pyometra , Animals , Dog Diseases/microbiology , Dogs , Escherichia coli , Female , Hemolysin Proteins , Peptide Hydrolases , Pyometra/veterinary , Siderophores , Virulence Factors
8.
Future Microbiol ; 17: 903-915, 2022 Aug.
Article in English | MEDLINE | ID: mdl-35748170

ABSTRACT

Candida nivariensis caused refractory esophagitis in a 36-year-old Brazilian man coinfected with HIV and Leishmania. A literature review on this rare fungal pathogen is also presented. The diagnosis was made, and pathogen identification was performed using matrix-assisted laser desorption ionization-time of flight mass spectrometry and sequencing of the LSU/26S region. An antifungigram was performed using broth microdilution. A literature search of PubMed was performed. The causative agent, C. nivariensis, was resistant to fluconazole and voriconazole. The patient's condition worsened considerably, and he passed away. This is the second report of this Candida species in Brazil and the first case reported worldwide of refractory esophagitis in a patient coinfected with HIV and Leishmania. The case illustrates the importance of precise identification and antifungal susceptibility testing when isolating this emerging pathogen.


Subject(s)
Esophagitis , HIV Infections , Adult , Antifungal Agents/pharmacology , Antifungal Agents/therapeutic use , Brazil , Drug Resistance, Fungal , Esophagitis/diagnosis , Esophagitis/drug therapy , Fluconazole/pharmacology , Fluconazole/therapeutic use , HIV Infections/drug therapy , Humans , Male , Microbial Sensitivity Tests , Saccharomyces cerevisiae , Saccharomycetales
9.
J Pharm Biomed Anal ; 216: 114788, 2022 Jul 15.
Article in English | MEDLINE | ID: mdl-35525110

ABSTRACT

Bacterial and fungal infections are challenging due to their low susceptibility and resistance to antimicrobial drugs. For this reason, antimicrobial peptides (AMP) emerge as excellent alternatives to overcome these problems. At the same time, their active insertion into the cell wall of microorganisms can be availed for biorecognition applications in biosensing platforms. Temporin-PTA (T-PTA) is an AMP found in the skin secretions of the Malaysian fire frog Hylarana picturata, which presents antibacterial activity against MRSA, Escherichia coli, and Bacillus subtilis. In this work, T-PTA was explored as an innovative sensing layer aiming for the electrochemical differentiation of Klebsiella pneumoniae, Acinetobacter baumannii, Bacillus subtilis, Enterococcus faecalis, Candida albicans, and C. tropicalis based on the structural differences of their membranes. The biosensor was analyzed through electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). In this approach, the different structural features of each microorganism resulted in different adherence degrees and, therefore, different electrochemical responses. The transducing layer was fabricated by the self-assembling of a 4-mercaptobenzoic acid (MBA) monolayer and gold-capped magnetic nanoparticles (Fe3O4@Au) implemented to improve the electrical signal of the biointeraction. We found that each interaction, expressed in variations of electron transfer resistance and anodic peak current, demonstrated a singular response from which the platform can discriminate all different microorganisms. We found expressive sensitivity towards Gram-negative species, especially K. pneumoniae. A detection limit of 101 CFU.mL-1 and a linear range of 101 to 105 CFU.mL-1 were obtained. The T-PTA biosensor platform is a promising and effective tool for microbial identification.


Subject(s)
Biosensing Techniques , Antimicrobial Cationic Peptides/chemistry , Biosensing Techniques/methods , Electrodes , Gold/chemistry
10.
J Mycol Med ; 32(1): 101213, 2022 Mar.
Article in English | MEDLINE | ID: mdl-34758424

ABSTRACT

Mycobacterium tuberculosis, which is responsible for tuberculosis (TB) and Cryptococcus sp. responsible for cryptococcosis, are pathogenic microorganisms that especially affect patients infected with the human immunodeficiency virus (HIV). Both diseases present similar classic symptoms, which makes diagnosis and treatment consequently difficult. To our knowledge, a few reported cases of M. tuberculosis and Cryptococcus sp. co-infection in non-HIV patients exist. This study reports a TB and neurocryptococcosis (NC) comorbidity case in a patient who had no clinical or serological evidence of HIV-compromised immunity. A 49-year-old male patient, a farmer with a low education level, previously diagnosed with TB and was undergoing treatment for a month when he presented progressive headaches, fever, drowsiness and photosensitivity, a stiff neck and a positive Lasègue test. During hospitalization, the patient was also diagnosed with NC through cerebrospinal fluid (CSF) analysis, which revealed the presence of capsulated yeasts by contrast with india ink. Following the yeast isolation, proteomic and molecular analyzes were performed. The patient received antifungal therapy in parallel with TB treatment, which caused complications and had to be modified twice. However, after three months of hospitalization the patient was discharged. Tuberculosis and cryptococcosis co-infection is a clinical and laboratory challenge, often leading to a delay in diagnosis. In this paper we emphasize the need to understand these infectious comorbidities in non-HIV patients from South America, since the few cases reported in the literature are from studies conducted in the United States and China.


Subject(s)
Cryptococcosis , Cryptococcus neoformans , HIV Infections , Tuberculosis , Comorbidity , Cryptococcosis/diagnosis , Cryptococcosis/drug therapy , Cryptococcosis/epidemiology , Cryptococcus neoformans/genetics , HIV Infections/microbiology , Humans , Male , Middle Aged , Proteomics , Tuberculosis/complications
11.
An Acad Bras Cienc ; 93(suppl 4): e20210823, 2021.
Article in English | MEDLINE | ID: mdl-34878053

ABSTRACT

Carbapenem-resistant P. aeruginosa (CRPA) has become a serious public health problem and the biofilm formation aggravates this problem. The study aimed to evaluate the occurrence of ß-lactamases and quorum sensing (QS) genes in CRPA isolates, analyze production of biofilm, evaluate the response against meropenem (MPM) and∕or polymyxin B (POL B) and its association with azythromicin (AZT) using quantum dots (QDs) and proteomic analysis. Six CRPA isolates were analyzed. ß-lactamases and QS genes were search using specific PCRs and were tested for biofilm production by quantitative technique. A CRPA isolate, containing blaKPC gene and biofilm-producing, was selected to assess its response to therapy using QDs and the MALDI-TOF. The ß-lactamase detected was blaKPC in 66.7% of the isolates. All isolates were biofilm producers and carriers of the QS genes. QDs-MPM conjugates triggered the formation of biofilm and the association with AZT inhibited this effect. Proteomics analysis showed that treatments with MPM or POL B suppressed the expression of the transglycosylase protein, while combined therapy with AZT induced expression of the RpoN protein. Thus, this study shows that the use of fluorescence combined with the proteomics analysis was promising to understand how a CRPA strain reacts to antimicrobial treatment.


Subject(s)
Pseudomonas Infections , Quantum Dots , Anti-Bacterial Agents/pharmacology , Carbapenems/pharmacology , Humans , Microbial Sensitivity Tests , Proteomics , Pseudomonas aeruginosa/genetics
12.
Future Microbiol ; 16: 1371-1379, 2021 12.
Article in English | MEDLINE | ID: mdl-34812048

ABSTRACT

Aim: Cases of sporotrichosis are emerging in several states of Brazil, especially in the southeast. Recently, sporotrichosis has been reported in the state of Pernambuco in the northeastern region. The goal of this study was to shed new light on sporotrichosis in terms of the geographic distribution of human cases and provide an overview of sporotrichosis associated with zoonotic transmission. Patients & methods: From March 2017 to November 2019, 179 patients were diagnosed with sporotrichosis. Georeferencing analysis, spatial distribution and epidemiological features of all cases are described. Results: The data show the dynamics of accelerated transmission of sporotrichosis across urban and coastal areas of the state of Pernambuco. Conclusion: There is a need to decentralize health services and implement a One Health approach to this emerging disease.


Subject(s)
Sporothrix , Sporotrichosis , Brazil/epidemiology , Humans , Sporotrichosis/epidemiology
13.
Microbiol Res ; 251: 126834, 2021 Oct.
Article in English | MEDLINE | ID: mdl-34364021

ABSTRACT

Biosensors are pre-prepared diagnostic devices composed of at least one biological probe. These devices are envisaged for the practical identification of specific targets of microbiological interest. In recent years, the use of narrow-specific probes such as lectins has been proven to distinguish bacteria and glycoproteins based on their superficial glycomic pattern. For instance, Concanavalin A is a carbohydrate-binding lectin indicated as a narrow-specific biological probe for Gram-negative bacteria. As a drawback, Gram-positive bacteria are frequently overlooked from lectin-based biosensing studies because their identification results in low resolution and overlapped signals. In this work, the authors explore the effect that platform nanostructuration has over the electrochemical response of ConA-based platforms constructed for bacterial detection; one is formed of chitosan-capped magnetic nanoparticles, and another is composed of gold nanoparticle-decorated magnetic nanoparticles. The biosensing platforms were characterized by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) as a function of bacterial concentration. Our results show that probe-target interaction causes variations in the electrical responses of nanostructured transducers. Moreover, the association of gold nanoparticles to magnetic nanoparticles resulted in an electrical enhancement capable of overcoming low resolution and overlapping Gram-positive identification. Both platforms attained a limit of detection of 10 ° CFU mL-1, which is useful for water analyses and sanitation concerns, where low CFU mL-1 are always expected. Although both platforms were able to detect Gram-negative bacteria, Gram-positives were only correctly differentiated by the gold nanoparticle-decorated magnetic nanoparticles, thus demonstrating the positive influence of hierarchically nanostructured platforms.


Subject(s)
Biosensing Techniques , Concanavalin A , Gram-Positive Bacteria , Biosensing Techniques/methods , Concanavalin A/pharmacology , Gold , Gram-Positive Bacteria/classification , Gram-Positive Bacteria/drug effects , Metal Nanoparticles , Transducers
14.
Talanta ; 220: 121375, 2020 Dec 01.
Article in English | MEDLINE | ID: mdl-32928401

ABSTRACT

Fungi stand out as primary pathogens present in healthcare-acquired infections, presenting an increased number of cases even using appropriate antifungal therapy. Candida spp. is a predominant microorganism among several fungal pathogens present in the healthcare setting. Candidemia and candidiasis are fungal infections responsible for high morbidity and mortality among ill patients in hospitals. It is noticeable that prolonged hospital stays lead to a higher economic impact and increased risk for developing secondary fungal or even bacterial infections. New fast and sensitive approaches for the detection of Candida species is highly required. Electrochemical biosensors are an excellent alternative to conventional techniques by combining fast analyte detection, low cost, and the possibility of miniaturization. Lectins are carbohydrate-binding proteins with the capability to reach out to the microorganism cell wall. In this work, we proposed the development of an impedimetric biosensor for Candida spp. based on Concanavalin A (ConA) and wheat germ agglutinin (WGA) as recognition agents of the yeast cells. Atomic force microscopy images indicate changes in the biosensor surface after assembly of the molecules and exposure to fungal samples. Electrochemical impedance spectroscopy results revealed a proportional increase of charge transfer resistance (RCT) as fungal CFU increased, where four Candida species were evaluated (Candida krusei, Candida tropicalis, Candida parapsilosis and Candida albicans). The biosensor is useful to differentiate Candida spp. with a detection limit between 102 to 106 CFU mL-1. The obtained biosensor appears as an innovative candidate for the detection and differentiation of pathogenic Candida spp.


Subject(s)
Biosensing Techniques , Candida , Antifungal Agents , Cell Differentiation , Humans , Lectins , Microbial Sensitivity Tests , Pichia
15.
Microorganisms ; 8(1)2020 Jan 13.
Article in English | MEDLINE | ID: mdl-31940988

ABSTRACT

Mass spectrometry by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) was used to identify and differentiate the pattern of susceptibility of clinical isolates of Candida parapsilosis complex. 17 C. parapsilosis sensu stricto, 2 C. orthopsilosis, and 1 C. metapsilosis strains were obtained from blood cultures, and three different inocula (103, 105, and 107 CFU/mL) were evaluated against three echinocandins at concentrations ranging from 0.03 to 16 µg/mL after incubation of 1 h, 2 h, and 3 h. Drug-free control was used. The spectra obtained at these concentrations were applied to generate composite correlation index (CCI) matrices for each yeast individually. After cross correlations and autocorrelations of each spectra with null (zero) and maximal (16) concentrations, the CCI was used as separation parameter among spectra. Incubation time and inoculum were critical factors to reach higher precision and reliability of this trial. With an incubation time of 3 h and inoculum of 107 CFU/mL, it was possible to determine the breakpoint of the clinical yeasts by MALDI-TOF that presented high agreement with the clinical laboratory standard institute (CLSI) reference method. Herein, we show that mass spectrometry using the MALDI-TOF technique is powerful when it exploits antifungal susceptibility testing assays.

16.
Mycopathologia ; 185(2): 395-398, 2020 Apr.
Article in English | MEDLINE | ID: mdl-31897974

ABSTRACT

Emergent fungal infections are uncommon conditions which frequently lead to death. To our knowledge, only a few cases of invasive infection by Cystobasidium minutum (previously known as Rhodotorula minuta) have been reported. Moreover, several factors are responsible for deep site infections, such as catheter-related fungemia. This report describes the first case report of Cystobasidium minutum causing fungemia in Brazil. The pathogens fungemia was demonstrated by catheter and blood culture-proven, and both yeasts were identified by sequences of D1/D2 rDNA region. After the end of antifungal therapy and catheter removal, a second blood culture was found to be negative and the clinical signs and symptoms of the patient improved.


Subject(s)
Basidiomycota/isolation & purification , Fungemia , Neoplasms/complications , Amphotericin B/administration & dosage , Amphotericin B/therapeutic use , Antifungal Agents/therapeutic use , Basidiomycota/classification , Basidiomycota/genetics , Brazil , Catheter-Related Infections/microbiology , DNA, Fungal , DNA, Ribosomal , Deoxycholic Acid/administration & dosage , Deoxycholic Acid/therapeutic use , Drug Combinations , Female , Fungemia/drug therapy , Fungemia/pathology , Humans , Immunocompromised Host , Microbial Sensitivity Tests , Middle Aged , Neutropenia
18.
Front Microbiol ; 7: 1783, 2016.
Article in English | MEDLINE | ID: mdl-27895625

ABSTRACT

Several studies have been developed regarding human health risks associated with the recreational use of beaches contaminated with domestic sewage. These wastes contain various micro-organisms, including Candida tropicalis. In this context, the objective of this study was to characterize C. tropicalis isolates from the sandy beach of Ponta Negra, Natal, Rio Grande do Norte, Brazil, regarding the expression of in vitro virulence factors, adaptation to osmotic stress and susceptibility to antifungal drugs. We analyzed 62 environmental isolates and observed a great variation among them for the various virulence factors evaluated. In general, environmental isolates were more adherent to human buccal epithelial cells (HBEC) than C. tropicalis ATCC13803 reference strain, and they also showed increased biofilm production. Most of the isolates presented wrinkled phenotypes on Spider medium (34 isolates, 54.8%). The majority of the isolates also showed higher proteinase production than control strains, but low phospholipase activity. In addition, 35 isolates (56.4%) had high hemolytic activity (hemolysis index > 0.55). With regard to C. tropicalis resistance to osmotic stress, 85.4% of the isolates were able to grow in a liquid medium containing 15% sodium chloride. The strains were highly resistant to the azoles tested (fluconazole, voriconazole and itraconazole). Fifteen strains were resistant to the three azoles tested (24.2%). Some strains were also resistant to amphotericin B (14 isolates; 22.6%), while all of them were susceptible for the echinocandins tested, except for a single strain of intermediate susceptibility to micafungin. Our results demonstrate that C. tropicalis isolated from the sand can fully express virulence attributes and showed a high persistence capacity on the coastal environment; in addition of showing high minimal inhibitory concentrations to several antifungal drugs used in current clinical practice, demonstrating that environmental isolates may have pathogenic potential.

19.
Exp Dermatol ; 25(1): 79-81, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26476093

ABSTRACT

White piedra is a fungal infection characterized by nodules comprised of Trichosporon species and restricted to the extrafollicular portion of the hair shaft. The diagnosis is based on clinical and mycological characteristics, and must be confirmed with a precise identification of the etiological agent. This research aimed to develop an in vitro infection model of white piedra and analyze its morphological and ultra-structural aspects. In the process, hair infection was induced using eight isolates of the genus Trichosporon maintained in the Culture Collection Micoteca URM. The ITS and IGS1 regions were sequenced for taxonomic confirmation. Scanning Electron Microscope (SEM) was performed at the Strategic Center for Northeast Technologies (CETENE). The scanning electron microscope was equipped with an Energy Dispersion Spectrometer (EDS). The Trichosporon isolates were identified as Trichosporon asahii (6) and Trichosporon montevideense (2) by internal transcript spacer (ITS) region and intergenic spacer 1 region (IGS1) sequencing. All eight strains were used to induce the in vitro hair infection, and nodules formed after the incubation period. Temperature variations and high humidity were not observed to be related to the development of this hair disease. The main chemical constituents detected in the nodules were carbon, nitrogen and oxygen, as well as a low level of sulfur. The absence of calcium, combined with the low level of sulfur, might explain the soft nature of the white piedra nodules. This study demonstrated that several Trichosporon species may be responsible for causing white piedra.


Subject(s)
Hair Diseases/microbiology , Microscopy, Electron, Scanning , Piedra/diagnosis , Piedra/microbiology , Calcium/chemistry , Hair/ultrastructure , Humans , Nitrogen/chemistry , Oxygen/chemistry , Sulfur/chemistry , Trichosporon
20.
Mycopathologia ; 180(1-2): 69-73, 2015 Aug.
Article in English | MEDLINE | ID: mdl-25666389

ABSTRACT

Candidemia is a frequent condition in Neonatal Intensive Care Units (NICU) and usually complicates the newborns clinical course. Several factors are responsible for candidiasis, such as prematurity and use of broad-spectrum antibiotics, and in these cases, there are the involvement of various Candida species, as C. albicans, and C. parapsilosis. However, other species as C. haemulonii has been rarely described in candidemia cases, being considered an emergent pathogen. Thus, we report a case of neonatal candidemia by C. haemulonii and a review of literature of fungemia by this yeast. The patient was a neonate with gestational age of 26 weeks and birth weight of 660 g hospitalized in a NICU from a Brazilian hospital. The identification of the etiological agent was performed by phenotypic methods, scanning electron microscopy, sequencing of the ITS region of rDNA, and mass spectrometry. Antifungal susceptibility testing was carried out according to the Clinical Laboratories and Standards Institute guidelines. The newborn was diagnosed with candidemia by C. haemulonii resistant to amphotericin B with minimal inhibitory concentration (MIC) of 8 µg/mL, sensitive to fluconazole (MIC: 8 µg/mL) and voriconazole (MIC: 0.12 µg/mL). The treatment with fluconazole (12 mg/kg/day) was established with good outcome. Candidemia by C. haemulonii is still being limited to a few sporadic cases in adults with endemic and restricted occurrences in neonates. Usually, the therapy with amphotericin B is ineffective against this species. Our results showed the importance of the mycological diagnosis associated to antifungigrama for the successful clinical management followed by important epidemiological data.


Subject(s)
Candida/isolation & purification , Candidemia/diagnosis , Candidemia/microbiology , Antifungal Agents/pharmacology , Antifungal Agents/therapeutic use , Brazil , Candida/classification , Candida/genetics , Candida/physiology , Candidemia/drug therapy , DNA, Fungal/chemistry , DNA, Fungal/genetics , DNA, Ribosomal Spacer/chemistry , DNA, Ribosomal Spacer/genetics , Drug Resistance, Fungal , Female , Humans , Infant, Extremely Low Birth Weight , Infant, Newborn , Mass Spectrometry , Microbial Sensitivity Tests , Molecular Sequence Data , Sequence Analysis, DNA , Treatment Outcome
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